Ms. Agrawal wants to do the most radical thing for derrière self-care since Mr. Whipple warned Americans not to squeeze the Charmin. Her clip-on bidet attachment, Tushy, is designed to lure wellness-minded millennials, with its sleek iPhone-inspired looks and $69 price tag (the Tushy Spa, with a warm-water function, costs $84).

“The time is now,” Tushy’s head of operations, Justin Allen, said. He cited the popularity of Squatty Potty, the posture-improving stool that appeared on “Shark Tank,” as well as Poo-Pourri — deodorizing bathroom sprays that come in Victorian era-looking bottles and have become a staple at upscale pharmacy counters — as evidence that America is ready to reassess its bathroom practices. (Perhaps this is a logical component of the current preoccupation with gut health.)

Bidets have long been popular on other continents but are largely unfamiliar in the United States, though a recent article in Vice’s wellness magazine, Tonic, argued that bidets are a more hygienic solution than toilet tissue, and an episode of “Keeping Up With the Kardashians” showed Kylie Jenner picking out a high-end Toto Washlet S350e personal cleaning system, with an automatically closing lid and a night light.

Could average Americans be ready to give this gadget a whirl?

On a recent morning, Ms. Agrawal was seated in the corner of a Chelsea coffee shop, wearing a white jacket with epaulets over a black leotard and no pants and nursing her 6-month-old son, Hiro. Hovering nearby were friends from an 80-person-strong group she calls her “Boom Spiral,” named after their Burning Man entourage in 2012.

A former semiprofessional soccer player, Ms. Agrawal showed no signs of fatigue, though she had spent the early hours dancing at Daybreaker, a morning rave party co-founded by her twin sister, Radha. It was their 39th birthday, and they had performed a celebratory crowd-surf while Hiro, wearing nothing but noise-canceling headphones and a diaper, rode around in a carrier on the chest of his father, Andrew Horn, the founder of Tribute, a company that makes video montages.

Eating a pesto omelet, Ms. Agrawal said that bidets have always been a part of her family’s culture: Her father is Indian, and her mother is Japanese. In 2012, when she and Mr. Horn had been dating for a few months, he gave her a Chinese bidet toilet attachment for Valentine’s Day. “I was like, ‘This is amazing, I didn’t know these existed,’” she said. “But it was so ugly and embarrassing.”

Rebranding the bidet became her side project, and in 2016 Tushy was quietly introduced. At the time, her main focus was Thinx, available since 2011. “We sold millions and millions of units — I can’t say more or I would get in trouble,” Ms. Agrawal said, referring to her separation contract.

“I learned a lot with my previous company,” she went on, eyes filling with tears. “I felt like I had to lead from a masculine place for so long, because I had to compete with men to raise money from men, and I had to deal with men all day long. Our board was men.”

She said she has raised $1.4 million for Tushy, a fraction of her previous company’s capital, and employs 11. But Ms. Agrawal said sales over Christmas were three times greater than the year before, and that when she appeared on the Home Shopping Network in early January, the channel sold out its supply — 532 bidets — in under 10 minutes.

Still, the product faces, yes, an upstream battle. “We have indoctrinated Americans into thinking that dry paper is going to clean you, and it’s not,” she said.

Proponents say that bidet use reduces urinary-tract infections by removing bacteria that can travel up to the bladder, but the evidence is inconclusive. A 2010 study conducted in Japan of 268 women revealed that habitual bidet users actually presented aggravated vaginal microflora. Bidet users were far more likely to show fecal bacteria as well as contamination by other pathogens than nonusers were.

Philip Tierno, a professor of microbiology and pathology at New York University School of Medicine, said that no method is enough to completely eliminate bacteria. “If you compare the bidet experience with wet wipes, there’s no contest,” he said. “The wipes work better.”

But Ms. Agrawal believes passionately in her product. She plans to introduce travel and baby bidets later this year. She is also looking forward to the publication of her book, “Disrupt-Her,” about female leadership, this fall from Hay House. She used Shakti, the shape-shifting Hindu goddess, as writing inspiration.

“She gets to embody so many sides of herself — there’s Kali, the fighter; Durga, the warrior; Parvati, the goddess of wisdom; Lalita, the sensual goddess,” Ms. Agrawal said. “As women, we have so many sides to ourselves, yet in business only the fighter or warrior gets to come out. What I realized is I don’t have to lead with a sword in my hand. I can lead sitting down.”